The polymerase chain reaction (PCR) was invented by Kary Mullis in 7985, and Mullis thus was awarded the Nobel Prize and obtained patent rights about the PCR (U.S. Pat. No. 4,683,195 and U.S. Pat. No. 4,683,202). The PCR is patentable because the PCR is an invention not a discovery, in other words, the biochemical reaction thereof is not existed in the nature. The PCR is a man-made reaction, and is applied to pair a DNA double helix and bases. There are two functions, four kinds of materials, and three step circulation in the PCR procedure. The two functions of the PCR are searching and replication. Via the PCR procedure, a specific base sequence having hundreds of base pairs (bps) can be searched out from nucleic acid molecules having millions upon millions of base pairs, and the specific base sequence can be replicated into more than one million duplications. The four kinds of materials are a DNA template, a pair of primers, deoxyribonucleotide triphosphates (dNTPs) and a polymerase. The primers are also called as nucleic molecules, and the length of the primer is in a range of about 25 to 30 bps.
Furthermore, the PCR procedure comprises the three steps as follows. (1) Denaturation step: the double strand DNA melts to single strand DNA at the temperature of 95° C. (2) Annealing step: the reaction temperature is decreased to about 30 to 65° C. to allow the primers to anneal with the complementary single strand DNA. (3) Extension step: the temperature is increased to about 65 to 75° C. to activate the DNA polymerase. At this step, the DNA polymerase synthesizes a new DNA strand complementary to the original DNA strand via adding dNTPs which are complementary to the original DNA strand in 5′ to 3′ direction. The three steps as set forth are called a cycle. The PCR procedure is accomplished to amplify a specific region of a DNA strand by adjusting cycles.
The PCR technique can be classified into a continuous movement of liquid and a stationary liquid. In a prior art of the continuous movement of liquid, the PCR device is manufactured by using three metal pieces to form three different temperature areas. The feature thereof is that a specific flow channel is formed on a glass substrate to provide a liquid to flow, and three different heat sources are disposed under the glass substrate to form the three different temperature areas. Therefore, when the liquid is dropped on the specific flow channel, the liquid can be flowed through the three different temperature areas by an external pump so as to accomplish the PCR procedure. Because the liquid is driven by the external pump, the external pump may increase the difficulty in the minimization manufacture.
Additionally, in a prior art of the stationary liquid (Science, vol 298, page 739, 2002), the PCR device comprises the water cooled top plate, the hot plate, and the two cubes. The water cooled top plate and the hot plate are respectively disposed on the top of the two cubes and the bottom of the two cubes. The sealed cavity is formed in the intermediate space of the two cubes to contain a liquid comprising an analyzer. The two different temperature plates, the water cooled top plate and the hot plate, can generate the temperature differences to drive the liquid to flow, and thus, to amplify the analyzer, such as a specific template. Furthermore, in another prior art, the PCR process is performed by an optical heating method (Physical Biology, vol 1, page 1-8, 2004). The optical heating method is achieved by using a far infrared ray to focus on a liquid, such that the temperature of the liquid can be increased to accomplish the PCR procedure. The optical heating method requires an optical system and an alignment device; it will increase difficulties on integrating with the optical system and the alignment device.